60. Usefulness of 3D Ultrasonography in Diagnosis of Hepatocellular Carcinoma and Its Invasively Growing Lesion: Deciding a Precise Target Volume in Radiation Therapy
Hirotoshi Kato, Shuji Yamada, Masao Ohto and Hirohiko Tsujii
Keywords: hepatocellular carcinoma, ultrasonography, Fusion 3D, contrast-enhanced Fusion 3D, contrast-enhanced CT scan
One half of local recurrences of hepatocellular carcinomas (HCC) treated with carbon ion therapy occurred in the tumors that had invasively growing parts in themselves. Vascular invasion is one of the most clinically problematic findings in HCC treatment. Therefore, more precise examination of invasively growing lesions is essential to advance clinical results in HCC treatment.
Ultrasonography (US) is an examination offering easy observation of the local environment and providing vascular information around the HCC. So, in 1995 we started the study of US for diagnosis of HCC, especially for diagnosis of both tumors and vascular structures with ultrasonographic three-dimensional images (Fusion 3D). We also started a study of Fusion 3D using a contrast agent (contrast-enhanced Fusion 3D). The US machine we used was an Aplio (Toshiba Medical Systems Co., Ltd.) and contrast agent was Levovist (Nihon Schering KK).
We investigated the characteristic features of HCC, including the usefulness of contrast -enhanced Fusion 3D in diagnosis of invasively growing lesions of HCC.
Study 1: Characteristic features of HCC in contrast-enhanced Fusion 3D
We performed contrast-enhanced Fusion 3D on 22 patients with histologically proven HCC (40mm or less in diameter) and 5 with metastatic liver cancer. The results were as follows. 1. We recognized a Network Pattern and Flush Sign as characteristic features of HCC that were thought to be contrast-enhanced vascular images (Figure and Table). None of these features were detected in the metastatic liver cancers. 2. All five HCCs 15mm or less in diameter had the Network Pattern and Flush Sign, 60% of which had early staining and 40% had late washout in the contrast-enhanced CT scan with bolus injection of a contrast agent.
Study 2: Diagnosis of invasively growing lesions of HCC with contrast-enhanced Fusion 3D
We performed contrast-enhanced Fusion 3D on 41 patients with histologically proven HCC. The results were as follows. 1. All the invasively growing lesions of HCC had the Network Pattern and Flush Sign. 2. We could detect the invasively growing lesions of HCC with contrast-enhanced Fusion 3D more easily than simple US for both 2D and 3D. 3. HCCs 15mm or less in diameter had no invasively growing lesions, 74% of HCCs more than 15mm in diameter had the lesions. 4. Sixty-seven percent of the invasively growing lesions detected with Contrast-Enhanced Fusion 3D could not be diagnosed by contrast-enhanced CT scan.
In conclusion, contrast-enhanced Fusion 3D may allow the diagnosis of HCC and its invasively growing lesions by such characteristic features as the Network Pattern and Flush Sign, and it may be superior to the contrast-enhanced CT scan especially in small HCC.
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